array_change_key_case

(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)

array_change_key_case — Changes the case of all keys in an array

Description

array_change_key_case(array $array, int $case = CASE_LOWER): array

Returns an array with all keys from array lowercased or uppercased. Numbered indices are left as is.

Parameters

array: The array to work on
case: Either CASE_UPPER or CASE_LOWER (default)

Return Values

Returns an array with its keys lower or uppercased.

Examples

Example #1 array_change_key_case() example

<?php
$input_array = array("FirSt" => 1, "SecOnd" => 4);
print_r(array_change_key_case($input_array, CASE_UPPER));
?>

The above example will output:

Array
(
    [FIRST] => 1
    [SECOND] => 4
)

Notes

Note:
If an array has indices that will be the same once run through this function (e.g. "keY" and "kEY"), the value that is later in the array will override other indices.

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User Contributed Notes 13 notes

down

qeremy [atta] gmail [dotta] com ¶

12 years ago

Unicode example;

<?php
function array_change_key_case_unicode($arr, $c = CASE_LOWER) {
$c = ($c == CASE_LOWER) ? MB_CASE_LOWER : MB_CASE_UPPER;
    foreach ($arr as $k => $v) {
$ret[mb_convert_case($k, $c, "UTF-8")] = $v;
    }
    return $ret;
}

$arr = array("FirSt" => 1, "yağ" => "Oil", "şekER" => "sugar");
print_r(array_change_key_case($arr, CASE_UPPER));
print_r(array_change_key_case_unicode($arr, CASE_UPPER));
?>

Array
(
    [FIRST] => 1
    [YAğ] => Oil
    [şEKER] => sugar
)
Array
(
    [FIRST] => 1
    [YAĞ] => Oil
    [ŞEKER] => sugar
)

down

xsaero00 ¶

10 years ago

Here is the most compact way to lower case keys in a multidimensional array

function array_change_key_case_recursive($arr)
{
    return array_map(function($item){
        if(is_array($item))
            $item = array_change_key_case_recursive($item);
        return $item;
    },array_change_key_case($arr));
}

down

zhangxuejiang ¶

4 years ago

I improve the array_change_key_case_recursive function ,let it can lowercase or uppercase keys

function array_change_key_case_recursive($arr, $case = CASE_LOWER)
{
    return array_map(function($item) use($case) {
        if(is_array($item))
            $item = array_change_key_case_recursive($item, $case);
        return $item;
    },array_change_key_case($arr, $case));
}

down

msegit post pl ¶

3 years ago

Improved multidimensional unicode func (after qeremy):
<?php
function array_change_key_case_unicode_recurs($arr, $c = CASE_LOWER) {
    foreach ($arr as $k => $v) {
$ret[mb_convert_case($k, (($c === CASE_LOWER) ? MB_CASE_LOWER : MB_CASE_UPPER), "UTF-8")] = (is_array($v) ? array_change_key_case_unicode_recurs($v, $c) : $v );
    }
    return $ret;
}

$arr = array("FirSt" => 1, "ZażóŁć gęŚlą jaŹń" => array("yağ" => "Oil", "şekER" => "sugar") );
print_r(array_change_key_case($arr, CASE_UPPER));
print_r(array_change_key_case_unicode_recurs($arr, CASE_UPPER));
?>

Array
(
    [FIRST] => 1
    [ZAżóŁć GęŚLą JAŹń] => Array
        (
            [yağ] => Oil
            [şekER] => sugar
        )
)
Array
(
    [FIRST] => 1
    [ZAŻÓŁĆ GĘŚLĄ JAŹŃ] => Array
        (
            [YAĞ] => Oil
            [ŞEKER] => sugar
        )
)

down

-2

gsoft ¶

1 year ago

//Array key case change recursively (Unicode):

<?php
function array_key_case($data,$case=FALSE)
{
$ret=array();
    if ( is_array($data) )            
        foreach ($data as $idx => $val)                   
$ret[$case ? mb_strtoupper($idx) : mb_strtolower($idx)]=array_key_case($val,$case);            
    else
$ret=$data;
    return $ret;
}

down

andreas dot schuhmacher87 at googlemail dot com ¶

16 years ago

multibyte and multi-dimensional-array support, have fun!

<?php
    define('ARRAY_KEY_FC_LOWERCASE', 25); //FOO => fOO
define('ARRAY_KEY_FC_UPPERCASE', 20); //foo => Foo
define('ARRAY_KEY_UPPERCASE', 15); //foo => FOO
define('ARRAY_KEY_LOWERCASE', 10); //FOO => foo
define('ARRAY_KEY_USE_MULTIBYTE', true); //use mutlibyte functions

    /**
    * change the case of array-keys
    *
    * use: array_change_key_case_ext(array('foo' => 1, 'bar' => 2), ARRAY_KEY_UPPERCASE);
    * result: array('FOO' => 1, 'BAR' => 2)
    *
    * @param    array
    * @param    int
    * @return     array
    */
function array_change_key_case_ext(array $array, $case = 10, $useMB = false, $mbEnc = 'UTF-8') {
$newArray = array();

//for more speed define the runtime created functions in the global namespace

        //get function
if($useMB === false) {
$function = 'strToUpper'; //default
switch($case) {
//first-char-to-lowercase
case 25:
//maybee lcfirst is not callable
if(!function_exists('lcfirst')) 
$function = create_function('$input', '
                            return strToLower($input[0]) . substr($input, 1, (strLen($input) - 1));
                        ');
                    else $function = 'lcfirst';
                    break;

//first-char-to-uppercase                
case 20:
$function = 'ucfirst';
                    break;

//lowercase
case 10:
$function = 'strToLower';
            }
        } else {
//create functions for multibyte support
switch($case) {
//first-char-to-lowercase
case 25:
$function = create_function('$input', '
                        return mb_strToLower(mb_substr($input, 0, 1, \'' . $mbEnc . '\')) . 
                            mb_substr($input, 1, (mb_strlen($input, \'' . $mbEnc . '\') - 1), \'' . $mbEnc . '\');
                    ');

                    break;

//first-char-to-uppercase
case 20:
$function = create_function('$input', '
                        return mb_strToUpper(mb_substr($input, 0, 1, \'' . $mbEnc . '\')) . 
                            mb_substr($input, 1, (mb_strlen($input, \'' . $mbEnc . '\') - 1), \'' . $mbEnc . '\');
                    ');

                    break;

//uppercase
case 15:
$function = create_function('$input', '
                        return mb_strToUpper($input, \'' . $mbEnc . '\');
                    ');
                    break;

//lowercase
default: //case 10:
$function = create_function('$input', '
                        return mb_strToLower($input, \'' . $mbEnc . '\');
                    ');
            }
        }

//loop array
foreach($array as $key => $value) {
            if(is_array($value)) //$value is an array, handle keys too
$newArray[$function($key)] = array_change_key_case_ex($value, $case, $useMB);
            elseif(is_string($key))
$newArray[$function($key)] = $value;
            else $newArray[$key] = $value; //$key is not a string
} //end loop

return $newArray;
    }
?>

down

-1

shaman_master at list dot ru ¶

4 years ago

<?php
/**
 * Convert keys in an array.
 * 
 * @param array $array Source data
 * @param callable $callback Function name (strtolower, strtoupper, ucfirst, lcfirst, ucwords)
 * @return array
 */
function array_convert_key_case(array $array, callable $callback = 'strtolower')
{
    return array_combine(
array_map($callback, array_keys($array)),
array_values($array)
    );
}
?>

down

-2

NetPanther ¶

11 years ago

Use this to capitalize first letter of all array keys:

<?php

function ucfirstKeys(&$data)
{
  foreach ($data as $key => $value)
  {
// Convert key
$newKey = ucfirst($key);

// Change key if needed
if ($newKey != $key)
    {
      unset($data[$key]);
$data[$newKey] = $value;
    }

// Handle nested arrays
if (is_array($value))
    {
ucfirstKeys($data[$key]);
    }
  }
}

$test = array('foo' => 'bar', 'moreFoo' => array('more' => 'foo'));
ucfirstKeys($test);
print_r($test);

?>

Result:
Array ( [MoreFoo] => Array ( [More] => foo ) [Foo] => bar )

down

-3

cm at gameswelt dot de ¶

17 years ago

I just changed the code a little bit so you havent got a code that repeats itself.

<?php

function array_change_key_case_secure($array = array(), $case = CASE_UPPER){
$secure = array();
$functionWrap = array(CASE_UPPER => 'strtoupper',
CASE_LOWER => 'strtolower');

    foreach($array as $key => $val){
        if(isset($functionWrap[$key])){
$key = $functionWrap[$case]($key);
$secure[$key][] = $val;
        } else {
            die('Not a known Type');
        }
    }

    foreach($secure as $key => $val){
        if(count($secure[$key]) == 1){
$secure[$key] = $val[0];
        }
    }

    return $secure;
}

$myArray = array('A' => 'Hello',
'B' => 'World',
'a' => 'how are you?');

print_r($myArray);
$myArray = array_change_key_case_secure($myArray);
print_r($myArray);

/*
Array
(
    [A] => Hello
    [B] => World
    [a] => how are you?
)
Array
(
    [A] => Array
        (
            [0] => Hello
            [1] => how are you?
        )

    [B] => World
)
*/

down

-4

anon at ymous dot com ¶

15 years ago

Below is a recursive version of this function.


<?php

/**

     * A recursive array_change_key_case function.

     * @param array $input

     * @param integer $case

     */

function array_change_key_case_recursive($input, $case = null){

        if(!is_array($input)){

trigger_error("Invalid input array '{$array}'",E_USER_NOTICE); exit;

        }

// CASE_UPPER|CASE_LOWER

if(null === $case){

$case = CASE_LOWER;

        }

        if(!in_array($case, array(CASE_UPPER, CASE_LOWER))){

trigger_error("Case parameter '{$case}' is invalid.", E_USER_NOTICE); exit;

        }

$input = array_change_key_case($input, $case);

        foreach($input as $key=>$array){

            if(is_array($array)){

$input[$key] = array_change_key_case_recursive($array, $case);

            }

        }

        return $input;

    }

?>

down

-5

Luis Henrique Pessoa ¶

13 years ago

Script to change case of sub-arrays keys:

<?php

function arrKey2Lower(&$arrVals) {
        foreach( $arrVals as $key => $item ) {
$key2 = strtolower($key);
            if ( $key2 != $key) {
                unset($arrVals[$key]);
$arrVals[$key2]=$item;
$key=$key2;
            }

            if ( is_array($item) ) { arrKey2Lower($arrValores[$key]); }
        }
    }

$arr = array('ID' => 1, 'NAME'=> 'Luis', 'Contact' => array('PHONE' => '3010-7148', 'E-MAIL' => 'luis@net.com') );
arrKey2Lower($arr);
var_dump($arr);


?>

outputs:

array(3) {
  ["id"]=>
  int(1)
  ["name"]=>
  string(4) "Luis"
  ["contact"]=>
  array(2) {
    ["phone"]=>
    string(9) "3010-7148"
    ["e-mail"]=>
    string(12) "luis@net.com"
  }
}

down

-5

john at doe dot com ¶

16 years ago

<?php
function array_change_value_case($input, $case = CASE_LOWER)
{
$aRet = array();

    if (!is_array($input))
    {
        return $aRet;
    }

    foreach ($input as $key => $value)
    {
        if (is_array($value))
        {
$aRet[$key] = array_change_value_case($value, $case);
            continue;
        }

$aRet[$key] = ($case == CASE_UPPER ? strtoupper($value) : strtolower($value));
    }

    return $aRet;
}
?>

down

-2

wendri dot net at gmail dot com ¶

1 year ago

Array of partitions with always the same number of sub-array indexes.

<?php

function partitionFixedSubArray($array, $length, $empty_space)
{   
$result = [];

    if ( sizeof($array) ) {

$result = array_chunk($array, $length);
$last_array_count = sizeof(end($result));

        if ($last_array_count < $length) {

            for ($i = $last_array_count; $i < $length; $i++) {
array_push($result[key($result)], $empty_space);
            }
        }
    }

    return $result;
}

$employees = [
"Paidi",
"Paijo",
"Darno",
"Kusnan",
"Mukidi",
"Sarno",
"Nurdin",
"Parmen",
"Sukinah",
"Sartini",
"Sukijan",
"Yono",
"Supoyo"
];

echo "<pre>";
print_r(partitionFixedSubArray($employees, 5, "empty space"));
echo "</pre>";

?>

Output:
Array
(
    [0] => Array
        (
            [0] => Paidi
            [1] => Paijo
            [2] => Darno
            [3] => Kusnan
            [4] => Mukidi
        )

    [1] => Array
        (
            [0] => Sarno
            [1] => Nurdin
            [2] => Parmen
            [3] => Sukinah
            [4] => Sartini
        )

    [2] => Array
        (
            [0] => Sukijan
            [1] => Yono
            [2] => Supoyo
            [3] => empty space
            [4] => empty space
        )

)

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